Summary
The rtMedia WordPress plugin has insufficient authorization and file path validation in its file-processing workflow, allowing unauthenticated attackers to delete certain arbitrary files on the server. The risk arises when the vulnerable endpoint accepts attacker-controlled file references and exposes a usable frontend nonce without requiring prior authentication.
The rtMedia WordPress plugin has insufficient authorization and file path validation in its file-processing workflow, allowing unauthenticated attackers to delete certain arbitrary files on the server. The risk arises when the vulnerable endpoint accepts attacker-controlled file references and exposes a usable frontend nonce without requiring prior authentication.
Affected context
The issue occurs in rtMedia deployments using the plugin's gallery or upload shortcode and its file-processing functionality. Frontend pages can expose the rtmedia_upload_nonce value to unauthenticated visitors, while insufficient validation of submitted file paths may allow deletion of files outside the intended upload location. The practical impact depends on filesystem permissions and which files are considered safe for deletion.
The issue occurs in rtMedia deployments using the plugin's gallery or upload shortcode and its file-processing functionality. Frontend pages can expose the rtmedia_upload_nonce value to unauthenticated visitors, while insufficient validation of submitted file paths may allow deletion of files outside the intended upload location. The practical impact depends on filesystem permissions and which files are considered safe for deletion.
Exploit preconditions
- Attack surface: The publicly reachable rtMedia upload or gallery workflow
in a WordPress site.
- Required access: No authenticated account is necessarily required; an
unauthenticated visitor may obtain the frontend nonce.
- Trigger point: File processing that handles a user-controlled file
reference or path.
- Why exploitation is possible: The workflow does not sufficiently authorize
the deletion operation or constrain the resolved path to the intended
storage area.
- Attack surface: The publicly reachable rtMedia upload or gallery workflow
in a WordPress site.
- Required access: No authenticated account is necessarily required; an
unauthenticated visitor may obtain the frontend nonce.
- Trigger point: File processing that handles a user-controlled file
reference or path.
- Why exploitation is possible: The workflow does not sufficiently authorize
the deletion operation or constrain the resolved path to the intended
storage area.
Why this happens
The underlying bug combines insufficient authorization with inadequate file path validation. A deletion routine accepts input associated with a client request without reliably proving that the requester is permitted to delete the target or that the target remains within an approved directory. This behavior maps to CWE-862, Improper Authorization, because a security-sensitive file operation can be reached without an effective authorization decision. Publicly emitted nonce values further weaken the assumption that possession of the request token represents authenticated user authority.
The underlying bug combines insufficient authorization with inadequate file path validation. A deletion routine accepts input associated with a client request without reliably proving that the requester is permitted to delete the target or that the target remains within an approved directory. This behavior maps to CWE-862, Improper Authorization, because a security-sensitive file operation can be reached without an effective authorization decision. Publicly emitted nonce values further weaken the assumption that possession of the request token represents authenticated user authority.
Potential impact
- An attacker may delete selected files that the web server can access.
- The plugin or surrounding WordPress application could experience
availability issues.
- Application content, media, or configuration-related files could be removed.
- Repeated abuse could cause data loss or disrupt site functionality.
- The affected site could require recovery from backups or other trusted copies.
- An attacker may delete selected files that the web server can access.
- The plugin or surrounding WordPress application could experience
availability issues.
- Application content, media, or configuration-related files could be removed.
- Repeated abuse could cause data loss or disrupt site functionality.
- The affected site could require recovery from backups or other trusted copies.
General mitigation guidance
Mitigation generally focuses on making file deletion explicitly authorized and limiting all file references to controlled storage locations. Secure patterns include performing server-side ownership and capability checks, resolving and canonicalizing paths before enforcing directory boundaries, allowing deletion only through opaque server-managed identifiers, and rejecting symlinks or paths that escape approved roots. Nonces should complement, rather than replace, authentication and authorization. File operations should run with the least filesystem privilege possible, and sensitive application files should not be writable or removable by the web process where feasible. Logging, rate limits, and recoverable backups can reduce the consequences of misuse.
Mitigation generally focuses on making file deletion explicitly authorized and limiting all file references to controlled storage locations. Secure patterns include performing server-side ownership and capability checks, resolving and canonicalizing paths before enforcing directory boundaries, allowing deletion only through opaque server-managed identifiers, and rejecting symlinks or paths that escape approved roots. Nonces should complement, rather than replace, authentication and authorization. File operations should run with the least filesystem privilege possible, and sensitive application files should not be writable or removable by the web process where feasible. Logging, rate limits, and recoverable backups can reduce the consequences of misuse.
How teams detect issues like this
Detection approaches include static analysis for file deletion APIs receiving request parameters, missing canonical-path checks, and authorization checks that rely solely on nonce validation. Code review should examine every path from upload, gallery, and shortcode handlers to filesystem operations, with particular attention to public nonce generation and capability enforcement. Runtime monitoring can alert on unusual deletion requests, repeated failures, or removals outside designated media directories. CI and policy checks can require approved path-handling utilities and explicit authorization before destructive operations; automated security review tools may help identify these patterns.
Detection approaches include static analysis for file deletion APIs receiving request parameters, missing canonical-path checks, and authorization checks that rely solely on nonce validation. Code review should examine every path from upload, gallery, and shortcode handlers to filesystem operations, with particular attention to public nonce generation and capability enforcement. Runtime monitoring can alert on unusual deletion requests, repeated failures, or removals outside designated media directories. CI and policy checks can require approved path-handling utilities and explicit authorization before destructive operations; automated security review tools may help identify these patterns.
